A Lotus japonicus cytoplasmic kinase connects Nod factor perception by the NFR5 LysM receptor to nodulation

The establishment of nitrogen-fixing root nodules in legume-rhizobia symbiosis requires an intricate communication between the host plant and its symbiont. We are, however, limited in our understanding of the symbiosis signaling process. In particular, how membrane-localized receptors of legumes activate signal transduction following perception of rhizobial signaling molecules has mostly remained elusive. To address this, we performed a coimmunoprecipitation-based proteomics screen to identify proteins associated with Nod factor receptor 5 (NFR5) in Lotus japonicus. Out of 51 NFR5-associated proteins, we focused on a receptor-like cytoplasmic kinase (RLCK), which we named NFR5-interacting cytoplasmic kinase 4 (NiCK4). NiCK4 associates with heterologously expressed NFR5 in Nicotiana benthamiana, and directly binds and phosphorylates the cytoplasmic domains of NFR5 and NFR1 in vitro. At the cellular level, Nick4 is coexpressed with Nfr5 in root hairs and nodule cells, and the NiCK4 protein relocates to the nucleus in an NFR5/NFR1-dependent manner upon Nod factor treatment. Phenotyping of retrotransposon insertion mutants revealed that NiCK4 promotes nodule organogenesis. Together, these results suggest that the identified RLCK, NiCK4, acts as a component of the Nod factor signaling pathway downstream of NFR5

100 ancient genomes show repeated population turnovers in Neolithic Denmark.

Major migration events in Holocene Eurasia have been characterized genetically at broad regional scales <sup>1-4</sup> . However, insights into the population dynamics in the contact zones are hampered by a lack of ancient genomic data sampled at high spatiotemporal resolution <sup>5-7</sup> . Here, to address this, we analysed shotgun-sequenced genomes from 100 skeletons spanning 7,300 years of the Mesolithic period, Neolithic period and Early Bronze Age in Denmark and integrated these with proxies for diet ( <sup>13</sup> C and <sup>15</sup> N content), mobility ( <sup>87</sup> Sr/ <sup>86</sup> Sr ratio) and vegetation cover (pollen). We observe that Danish Mesolithic individuals of the Maglemose, Kongemose and Ertebølle cultures form a distinct genetic cluster related to other Western European hunter-gatherers. Despite shifts in material culture they displayed genetic homogeneity from around 10,500 to 5,900 calibrated years before present, when Neolithic farmers with Anatolian-derived ancestry arrived. Although the Neolithic transition was delayed by more than a millennium relative to Central Europe, it was very abrupt and resulted in a population turnover with limited genetic contribution from local hunter-gatherers. The succeeding Neolithic population, associated with the Funnel Beaker culture, persisted for only about 1,000 years before immigrants with eastern Steppe-derived ancestry arrived. This second and equally rapid population replacement gave rise to the Single Grave culture with an ancestry profile more similar to present-day Danes. In our multiproxy dataset, these major demographic events are manifested as parallel shifts in genotype, phenotype, diet and land use

Two Legionnaires' disease cases associated with industrial waste water treatment plants: a case report

<p>Abstract</p> <p>Background</p> <p>Finnish and Swedish waste water systems used by the forest industry were found to be exceptionally heavily contaminated with legionellae in 2005.</p> <p>Case presentation</p> <p>We report two cases of severe pneumonia in employees working at two separate mills in Finland in 2006. <it>Legionella </it>serological and urinary antigen tests were used to diagnose Legionnaires' disease in the symptomatic employees, who had worked at, or close to, waste water treatment plants. Since the findings indicated a <it>Legionella </it>infection, the waste water and home water systems were studied in more detail. The antibody response and <it>Legionella </it>urinary antigen finding of Case A indicated that the infection had been caused by <it>Legionella pneumophila </it>serogroup 1. Case A had been exposed to legionellae while installing a pump into a post-clarification basin at the waste water treatment plant of mill A. Both the water and sludge in the basin contained high concentrations of <it>Legionella pneumophila </it>serogroup 1, in addition to serogroups 3 and 13. Case B was working 200 meters downwind from a waste water treatment plant, which had an active sludge basin and cooling towers. The antibody response indicated that his disease was due to <it>Legionella pneumophila </it>serogroup 2. The cooling tower was the only site at the waste water treatment plant yielding that serogroup, though water in the active sludge basin yielded abundant growth of <it>Legionella pneumophila </it>serogroup 5 and <it>Legionella rubrilucens</it>. Both workers recovered from the disease.</p> <p>Conclusion</p> <p>These are the first reported cases of Legionnaires' disease in Finland associated with industrial waste water systems.</p

Population genomics of post-glacial western Eurasia.

Western Eurasia witnessed several large-scale human migrations during the Holocene &lt;sup&gt;1-5&lt;/sup&gt; . Here, to investigate the cross-continental effects of these migrations, we shotgun-sequenced 317 genomes-mainly from the Mesolithic and Neolithic periods-from across northern and western Eurasia. These were imputed alongside published data to obtain diploid genotypes from more than 1,600 ancient humans. Our analyses revealed a 'great divide' genomic boundary extending from the Black Sea to the Baltic. Mesolithic hunter-gatherers were highly genetically differentiated east and west of this zone, and the effect of the neolithization was equally disparate. Large-scale ancestry shifts occurred in the west as farming was introduced, including near-total replacement of hunter-gatherers in many areas, whereas no substantial ancestry shifts happened east of the zone during the same period. Similarly, relatedness decreased in the west from the Neolithic transition onwards, whereas, east of the Urals, relatedness remained high until around 4,000 BP, consistent with the persistence of localized groups of hunter-gatherers. The boundary dissolved when Yamnaya-related ancestry spread across western Eurasia around 5,000 BP, resulting in a second major turnover that reached most parts of Europe within a 1,000-year span. The genetic origin and fate of the Yamnaya have remained elusive, but we show that hunter-gatherers from the Middle Don region contributed ancestry to them. Yamnaya groups later admixed with individuals associated with the Globular Amphora culture before expanding into Europe. Similar turnovers occurred in western Siberia, where we report new genomic data from a 'Neolithic steppe' cline spanning the Siberian forest steppe to Lake Baikal. These prehistoric migrations had profound and lasting effects on the genetic diversity of Eurasian populations

Legionella

Although legionnaires' disease frequently is acquired in health care institutions, little is known about the occupational risk of Legionella infection among health care workers. The aim of the present cross-sectional study was to analyse antibody levels among exposed hospital workers and to determine the correlation between antibodies to Legionella and self-reported symptoms. The study included 258 hospital employees and a reference group of 708 healthy blood donors. Hospital workers had a higher prevalence of Legionella antibody titres (≥1 : 128) than blood donors (odds ratio 3.4; 95% CI 2.4–4.8). Antibody levels were not higher among staff members at risk of frequent aerosol exposure than among less exposed employees. There was no consistent association between a history of influenza-like symptom complex and the presence of antibodies. The results indicate that hospital workers have a higher risk of Legionella infections than the general population. However, since no excess morbidity was associated with seropositivity, most Legionella infections may be asymptomatic

Enzyme immunoassay for detection of immunoglobulin M (IgM) and IgG antibodies to Mycoplasma pneumoniae.

An enzyme immunoassay (EIA) for detection of immunoglobulin M (IgM) and IgG antibodies to Mycoplasma pneumoniae was developed. The EIA was evaluated on the basis of results in the M. pneumoniae complement fixation (MPCF) test and the cold agglutinin test. Serum samples from 430 patients with respiratory infections of known or unknown etiology, from 91 healthy children and adults and from 20 patients with rheumatoid factor, were investigated. By the criteria chosen for positive diagnostic EIA values, we found that the combined measurement of specific IgM and IgG gave a specificity of 99.7% and a sensitivity of 97.8%. If only IgM antibodies were measured, the specificity was 100% and the sensitivity was 88%. For IgG alone the specificity was 99.7%, but the sensitivity was only 46% because of the high EIA cutoff value chosen for IgG. We found no false positives among serum samples from patients with non-M. pneumoniae respiratory infection of known etiology, and there were no false IgM positives due to rheumatoid factor. In some cases the IgM EIA results became positive earlier in the course of illness than the MPCF titer. While children and teenagers responded predominantly with IgM antibodies, patients older than 40 years often had an IgG response only (56% of cases), probably because of reinfection. We conclude that this EIA is a good alternative to the combined MPCF and cold agglutinin tests in the diagnosis of M. pneumoniae infection